The invention has particular application to snowthrowers and consequently will be described in the following with specific reference to that application. It is to be understood that other applications are intended to be included within the scope of this application.
In known snowthrowers, the blades are helical auger flights that intersect axial planes along lines at right angles to the axis. In use, the blade is driven sideways against snow to be removed so that the blade scrapes off snow and advances it towards a discharge, either at the end of the blade casing or in the center, depending on the blade configuration. At the discharge, an extruder throws the snow through a chute that is adjustable to control the distance and direction of throw. Advancing this type of auger blade arrangement against snow requires considerable effort, so that throwers of any significant size are usually propelled by driven wheels or tracks. Similar characteristics are found in digging implements for earth and sand which employ similar auger arrangements.